Module-internal object references are Rust types now (values, Arc,
Mutex); CHandle remains only at the oakengine C-ABI boundary:
- oakundo: the global stack holds UndoStack/UndoCommand values
directly (stack token is the static's address)
- oaktimeline: marker/workarea boxes carry Arc<Mutex<T>>; commands
share the same allocation through Arc clones (readers in oakengine
stubs and the app's graphops updated to lock)
- oaktask/oakstorage: sessions, write-through bindings and the
database backend pass ProjectArc; the Session drops its manual
release bookkeeping; nodeutil keeps the CHandle<->Arc boundary
conversion (release_project restored for the app)
- oakcodec: handle.rs deleted outright (no facade entry needed it);
texture/block placeholders are unit structs
- oakrender: copier's project handle is an identity u64; alive-count
machinery removed; handle.rs is make_owned/get/get_mut only
- oakplugin: the instance registry is gone (its unregister key never
matched, leaking weak entries); handle.rs is the RefBox boundary type
- oaknode/oakcommon: only dead guard/borrow helpers removed; external
payload handles (texture/processor) documented as the boundary
Flake hunts landed along the way: the audio recording test serializes
on the shared manager lock with a normalized state; the autocacher
cancel test uses a slow producer so cancellation is deterministic.